As in he believes he had to prove, and has to keep proving, to Broncos coach Gary Kubiak that he isn't just some one-down, speed option. That he's isn't just a first- and second-down player, a change-of-pace guy.
Hillman can play in the Broncos' backfield in whatever situation the team is in. So while his 7.4 yards per carry average certainly got the Broncos' attention in the preseason -- most by any player in the league with at least 20 carries in preseason games -- it was what Hillman did when he didn't have the ball that has put him getting most of the carries C.J. Anderson doesn't.
"I like what I've seen, I'm expecting him to have a great year," Kubiak said. "I think he's come into his own, think he's a very dynamic player, got big-play ability. But the thing I like about him is he's proven to me he can stay on the field for all three downs. I like the way he's picked up blitzes in the preseason, I think that's where he's improved the most."
When the Broncos waived Montee Ball, their second-round pick in the 2013 draft and the guy who was the starter when the 2014 season opened, it was an indication of how much faith the they have put in Hillman. In his previous three seasons, Hillman has alternately flashed both talent and immaturity in how he went about his football business.
But with the arrival of a new coaching staff, along with perhaps his 24th birthday, Hillman flourished in the new offense in the preseason and moved from the we'll-see spot of No. 3 running back to No.2 and that-guy-has-to-get-some-carries status. Hillman believes it happened because he showed the Broncos he can do more than just be a fast guy who gets a few touches.
"You always want to be on the field as long as possible," Hillman said after Monday's practice. "A lot of people are just saying ‘he's just a speed guy.' I've been doing it so it's nothing new to me, but I think I did have to show what I could do to (Kubiak)."
The scheme Kubiak has been a part of over the years -- since he was quarterbacks coach for the Super Bowl-winning 49ers team in the 1994 and on Mike Shanahan's staff in Denver for two more Super Bowl wins -- is a powerful carrot to running backs. Back after back, season after season, almost regardless of draft pedigree or previous résumé, the system has churned out productive rushers.
Last season, in Kubiak's lone season as the Baltimore Ravens' offensive coordinator, Justin Forsett rushed for 1,256 yards, or 647 more yards than he had rushed for in any previous season in his career. There are several scouts around the league who will say they have believed Hillman would be a quality fit in the offense.
Something Hillman believes as well, having been in a similar offense for his two seasons at San Diego State when he topped 100 yards in 15 of his 26 career games.
"You see guys like Arian Foster and (Justin) Forsett and they did pretty damn good -- Terrell Davis, Alfred Morris in his rookie year … everybody knows a zone scheme is definitely a fun scheme to run in,'' Hillman said. "Luckily for me I've done it in college, I know it."